Alternate action/operation mechanism



Jan. 24, 1967 G. J. BURY ALTERNATE ACTION/OPERATION MECHANISM 2 Sheets-Shee l Filed March 29, 1965 I NVENTOR. `George J. Bury G. J. BURY ALTERNATE ACTION/OPERATION MECHANISM Filed March 29, 1965 Jan. 24, 1967 INVENTOR. George J Burry Hfs Aff'ys United States Patent iice Patented Jan. 24, 1967 3,300,611 ALTERNATE ACTION/ OPERATION MECHANISM i George J. Bury, Antioch, Ill., assignor to Illinois Tool Works Inc., Chicago, Ill., a corporation of Delaware Filed Mar. 29, 1965, Ser. No. 443,554 14 Claims. (Cl. 200--156) The present invention relates to a new and improved alternate action mechanism for control devices such as switches, and more particularly, to a mechanism which maintains a control device in either of two states when operated.

Many commercial applications in the electrical control eld require the use of plunger operated mechanisms, as distinct from toggle `and other overcenter mechanisms, which alternatively lock a control device such as a switch upon successive depression thereof to energize or deenergize a circuit. Such mechanisms are commonly referred to as alternate action mechanisms because they provide alternate operation of a switch or control device upon successive ldepression of a plunger member.

While prior devices of this type have been generally satisfactory for the purposes intended, difficulty has been encountered in establishing a mechanical drive connection and removing or incapacitating this connection upon successive strokes of the plunger member. To operate reliably over long periods, the force generated by the plunger must be effectively transferred on its forward stroke, and on its return stroke, this connection must be broken to permit separation of thel parts, but without interrupting or hindering. the establishment of a positive drive connection during succeeding operations. Lost motion connections have previously been incorporated in alternate action mechanisms, but they have not provided both a positive actuation and release which is so necessary for reliable and continued operation over long` periods.

Accordingly, it is an object of the present invention to provide an alternate action mechanism which incorporates a new and improved lost motion connection.

More particularly, it is an object of the present invention to provide an `alternate action mechanism having a positive, non-slip connection when actuated by a plunger member on its forward stroke, and which is disabled or incapacitated on the return stroke of the plunger.

Yet more specifically, it is an `object of the present invention to provide an improved pawl-ratchet type of alternate action mechanism wherein the pawl is-designed to engage the ratchet teeth over a large surface area thereof to effectively transmit force from the pawl to the ratchet member as the latter is rotatively displaced in an incremental fashion by the pawl, and upon return of the pawl, permitting it to be moved past the ratchet member without disturbing the position thereof.

Still another object of the present invention is the provision of an improved alternate action mechanism of the type described in the preceding objects which, because of its construction, can be reliably operated in a repetitive fashion over long periods.

A further object of the present invention is the provision of an improved alternate `action mechanism of the type described in the foregoing objects wherein the parts thereof are structurally interrelated to each other for maximum utilization of mechanical advantage during their operation.

A still further object of the present invention is .to provide an improved alternate action mechanism made of durable parts, which is simple in operation and rugged in construction. l

Yet another object of the present invention is the provision of an improved alternate action mechanism which is sensitive to a low operating force, while also being relatively tease proof and shock-vibration resistant.

Other and further objects invented of the present invention Will be apparent from the following description when taken in connection with the accompanying drawings, wherein:

FIG. l is `a side elevational View, partly vin section, showing one form of alternate action mechanism as used in conjunction with a switch assembly;

FIG. 2 is a left end elevational View of the FIG. l embodiment;

FIG. 3 is an enlarged fragmentary elevational view showing the movement of various parts constituting the alternate action mechanism when displaced downwardly;

FIG. 4 is also an enlarged fragmentary elevational view showing movement of various parts of the alternate action mechanism when displaced upwardly;

FIG. 5 is a side elevational view, partly in section, of another form of alternate action mechanism also used with a switch assembly; and

FIG. 6 is a side elevational view, partly in section, of the alternate action embodiment shown in FIGS. 1-4 as used with a lighted push button switch assembly.

Referring now to the drawings, and first to the form of invention shown in FIGS. 1-4, there will be seen a switch assembly 10 which essentially comprises a hollow casing or bracket member 20 having a pair of switches 40 attached thereto adjacent one end thereof, a reciprocating plunger member 50 capable of being moved into and out of the hollow casing or bracket member, and an alternate action mechanism 60 positioned in the hollow casing between the switches 40 and the reciprocating plunger member 50.

The hollow casing of bracket member 20 is provided with a pair of spaced, generally parallel depending arms 22, 24 which extend downwardly from a connecting web or bight end portion 26. The switches 40 are assembled in side by side relationship within the housing 20 and are secured to the lower or free ends of the arms 22, 24 by suitable fastening means (not shown). Attached to the connecting web or bight end portion 26, in a central location thereof, is an externally threaded stud or tubular element 28. Nut members 30, 32 are threadably associated ot the stud or tubular element 28, and together with the lock Washer 34, mount the entire assembly 10 to the panel 36 as is illustrated in FIG. l of the drawings.

Each switch assembly is preferably provided with at least a pair of switches 40 which are attached to the lower or free ends of the arms 22, 24, lbut it will be understood that the number of switches disposed between the leg or arm elements can be varied as desired, it only being necessary to xedly -mount one switch between the leg or arm elements 22, 24 to form the switch assembly 10. The switches 40 are preferably of the precision switch type as shown, for example, in U.S. Patent No. 2,840,657 dated June 24, 1958. The switch shown in the aforementioned patent has a spring loaded depressor or actuator button 42 which isbiased outwardly of the switch casing by coil spring means 44. The switch actuator or button 42 controls the movement of contact members 46 between the fixed contacts 45, 47. Terminal means 48, which are connected to xed contacts 45, 47, extend downwardly beyond the lower or free ends of the arms 22, 24 for attachment to wire conductors. It is important to note that the particular details of the switches 40 form no part of the present invention, and that switches which are to be used in the switch assem- -bly 10 need only be of the type having switch actuator or depressor buttons which are spring loaded or biased toward a return position by suitable spring means as above described.

The plunger or push butt-on 50 depicted in FIGS. Vl-4 is shown as being integrally secured to a. pl-ate or lever 70 which forms part of the alternate :action mechanism 60. This is not always necessary as will be explained in connection with the other embodiments of the invention. The plunger or push but-ton 50 is suitably dimensioned so that it fits within the bore of stud or tubular element 28 for free movement therewithin. The uppermost portion of the plunger or push button projects upwardly beyond the stud or tubular element 28 a suicient distance to permit either manual or mechanical engagement. When the plunger or push button 50 is depressed, the a1- ternate action mechanism 60, to be presently described, will function to alternately depress and release the spring loaded spring actuators or buttons 42 of the switches 40 to provide successive opening and closing of circuits with which the switches 40 are connected.

As best seen in FIG. 1, the basic components of the alternate action mechanism 60 include an elongated plate or lever 70, a pawl member 80 pivotally mounted thereto and adapted to coact with a unit-ary or combination camratchet means 90 which, in turn, is operative to alternately depress and release the switch actuator or depressor buttons 42 of the switches 40 either directly or indirectly through a depressor plate 110. y

In the embodiment shown in FIGS. 1-4, the elongated plate 4or lever 70 is yadapted to be moved by the integral plunger or push button S in a reciprocatory fashion within the hollow casing of bracket member 20. The plate or The cam-ratchet combination 90 is rotatably disposed on a shaft 92 which extends between the depending arms 22, 24 of the casing 20. This cam-ratchet combination is subdivided into a ratchet gear 94 and a cam member 96 which are either integrally or otherwise operatively secured to one another. Ratchet gear 94 has a plurality of radially extending teeth 98, each of which are provided with a leading surface 97 and a trailing surface 99. The ratchet gear 94 and the teeth 98 :thereof are so rel-ated to the pawl member 80 that downward movement thereof causes the first finger portion 82 to engage, along its lower face, the entire surface area of leading surface 97. The

engagement between first finger portion 82 and the leadlever 78 is restrained from all but reciprocatory movement by being integrally connected to the plunger or pushbutton 50 which is limited to reciprocating movement within the bore of the stud or tubular element 28. The elongated plate or :lever 78 is re-siliently urged toward the reciprocating plunger or push button 50 bysear spring 72, one

The plate or lever 70 is provided with a channel 76 .l

which opens up into the lower face of the plate or lever 70 for accepting a portion of pawl member 80. vA secondary opening 77 which is inclined at an angle to the plunger or push button is formed inthe plate or lever 70, .and extends from the bottom margin of the channel 76 at one end thereof `to provide a suitable receiving aperture for one end of the helical coil compression spring means 78.

The pawl member 80 is pivotally mounted by way of shaft 79 to the plate or lever 70 within the channel 76 thereof. When the pawl member 80 is thus mounted to the plate or lever 70, its lower portion will extend downwardly beyond the lower face of the plate or lever 70 to present first and sec-ond `generally inflexible finger portions 82, 84 respective-ly which extend on lopposite sides of a vertical plane passing through the pivot shaft 79. Second finger porti-on 84 serves as an abutment or shoulder for one end of the helical coil spring means 78 to maintain the spring means 78 in the opening 77 formed in the plate or lever 70. The spring 78, when mounted in the manner shown in FIG. 1 of the drawings, will be compressively loaded to resiliently urge the pawl member 80 in a clockwise direction as viewed in FIGS. 1 and 3-4.

The firs-t linger portion 82 of the pawl member 80 is adapted to cooperate with ratchet gear 94 of combination cam-ratchet means 90 in a manner to be presentlydescribed.

40 button 50 and the ratchet gear 94.

ing surface 97 of one tooth 98 prior to movement of the ratchet gear-94A occurs when the pawl member is moved from Ithe FIG. l t-o the full line position shown in FIG. 3. It is to be specifically noted that the third inflexible finger portion 86 of pawl member 80 is adapted to abut against bottom marginal portions adjacent channel 76 to maintain the lower face of pawl member in a predetermined attitude when moved downwardly by lever 70. In the embodiments shown, the lower face of the pawl member is adapted'to be positioned and maintained in a substantially horizontal plane when displaced downwardly,

and the leading surface 97 of the tooth to be engaged is also positioned in a substantially horizontal plane. As a result,'the initial engagement between the first portion 82 and one of the teeth 98 will be across the entire'surface area of the tooth leading surface 97 so as to provide an effective `transfer of theforce from the plunger or push button 50 to the ratchet gear 94 and thus to the cam member 96. 'Continued relative movement between the pawl member 80 and the ratchet -gear' 94 from the'full to the dotted 'line positi-on'shown in'FIG. 3 of the drawings will cause the loweriface'of first finger portion 84 to engage first thefleading surface 97 of the engaged tooth and `then the 'upper surface 100 thereof to transmit Iforce in a positive`,.continuous mann-er between the plunger or push AAs the pawl member 80 is moved from the full to the dottedline position shown in FIG. 3, the ratchet gear 94 will ybe rotated through a 45 arc, and since the cam member96 is operatively 'secured thereto, it will also be rotated through a 45 '.arc. The cam member'96 als-o has a plurality of teeth 102,l1but this will be half as'rnany'as `the teeth providedlon the ratchet gear 94. As illustrated in the drawingsythe ratchet gear haseight teeth 98l while the -cam member has only four teeth 102. Teeth 102 extend from an .enlarged hub portion 104 whichhas a diameter at .least .asv great as'the radial extent of teeth 98 of the ratchet gear. As the cam member rotates, the teeth 102 thereof are alternatively moved into and out of engagement with the depressor plate 110 to alternatively actuate and release the switch actuator buttons 42.4

The depressor plate 110, which is pivotally mounted to vthe Acasing or bracket 'by way of shaft V112, has a plurality of arms lcorresponding in number and aligned with the switch actuator or depressor buttons 42 for engagement thereby. yOne of thearms of the depressor plate 110 is also aligned with the cam member 96 for positive coaction therewith in alternately depressing and .releasing the switch actuator or depressor buttons 42 of the switches 40. As best seen in FIGS. 1 and 3 of the drawings, the arm which is aligned with the cam member 96 has a V- shaped formation 114 at its outer free extremity to present a pair of convergent ramp surfaces 116, 118 along the upper face thereof as the cam member 96 is moved from the full to the dotted line position shown in FIG. 3 of the drawings. A curvilinear portion of the external peripheral surface on enlarged hub 104 will be moved past the ramp surfaces 116, 118, and a tooth 102 of the cam member will be slid down the ramp surface 116 for retention between vsurfaces A116, 118 as will be apparent. When the lever 70 and pawl 80 are moved or returned to their upper position, the cam-ratchet means will be retained in place by the tooth 102 of cam member 96 held captive by the ramp surfaces 116, 118. Subsequent depression of the plunger or push button 50 will, of course, again rotate the combination cam-ratchet means 90 to position the cam member 96 thereof from the dotted to the full line position shown in FIG. 3, thus moving the captive tooth 102 up ramp surface 118 and out of engagement with surfaces 116, 118 so that the switch actuator or depressor buttons 42 will be moved from their fully depressed to their released positions. It is to be noted that the arrangement between the cam-ratchet means 90 and the depressor plate 110 is such that they do not need separate or built in resiliency since sufficient spring biasing force is supplied by the springs 44 of switches` 40.

As has been discussed above, the lower face of pawl member 80 is maintained in a predetermined attitude when moved downwardly by the push button or plunger 50 for initial full face engagement with the leading surface 97 and subsequent engagement with the surface 100 of the engaged tooth to provide an effective arrangement for transmitting force between the push button or plunger 50 and the ratchet gear 94.` The manner in which the lower face of pawl member 80 engages first the leading surface `97 and then upper surface 100 of the engaged tooth is readily depicted in the full and dotted lines shown in FIG. 3 of the drawing. While this arrangement is desirable for the reasons above stated, it will be noted that thel pawl member 80, when in its lowermost position, will have the first finger portion 82 thereof positioned in a complementary recess 95 formed between each pair of adjacent teeth 98. This will make it impossible for the lever 70 and its associated pawl member 80 to return to their initial position unless some type .of release mechanism is provided which will enable the pawl member 80 to be rotatably displaced out of engagement with the ratchet gear 94 and returned to a position for subsequent full face engagement with the teeth 98 of ratchet gear 94. Y

In accordance with the present invention, it will be noted that the second finger portion 84 is biased outwardly away from the lower face of the lever 70 by the compressive coil spring means 78. The part of the channel 76 immediately above the second finger portion 84 spaces this finger portion a sufficient distance away from the lever 70 to prevent engagement therewith. Thus, when the plunger or push button y50 is released, the first finger portion 82 will be directed against the lower surface 101 of the engaged tooth, and since the pawl member 80 is capable of yielding in the area of the second finger portion V84, the pawl member 80 will be rotatably displaced to begin disengagement between the pawl member 80 and the ratchet gear 94. The first finger portion 82 will then be engaged by t-he trailing surface 99 of the engaged tooth to maintain the rotatably displaced pawl in a predetermined position until the first finger portion slides past and out of engagement with the trailing surface 99 for return to its initially cocked position.

This relative movement of the parts is readily depicted in FIG. 4 of the drawings where the pawl member is shown in full lines in its lowermost position, and then in dotted lines as it is moved upwardly and away from the ratchet gear 94.

The coil spring 78 is of sufficient strength to return the pawl member 80 to its initial position as shown in FIG. 1 of the drawings, but cannot either maintain the pawl 80 in its fixed attitude to rotate the ratchet gear 94 or hinder the return of lever 70 by way of sear spring 72. In other words, -the sear spring 72 is substantially stronger than the coil spring 78 to return the lever to the position shown in FIG. 1 withoutinterference from the coil spring 78, and the structural cooperation between the cam member 96 and the depressor plate 110 is stronger Y than the compressive strength of coil spring 78v to preratchet gear 94.

vent reverse rotation of the cam-ratchet means 90 as the lever 70 and its pawl member 80 are moved to the FIG. 1 position.

The pawl member is mounted on the face of lever 70 which is opposite to that of the plunger or push button 50 to obtain the benefit of direct engagement therewith over a substantial area which is only slightly offset from the plunger axis for effective transfer of force from the plunger or push button S0 to the cam-ratchet means through the engagement between the lever 70 and pawl member 80 as well as the pivot shaft connection therewith. In the usual case, the face of the lever which is opposite to the plunger or push button 50 will be the lower face thereof, and thus the entry of foreign particles of dirt, dust and the like, which could interfere with the operation, will be prevented to a great degree particularly in view of the fact that the spacing between the lever and pawl member at any time during the cycle of operation is relatively small. Aside from this, the simple and rugged structural arrangement of parts, which are themselves preferably made of a durable plastic material, provides a reliable, long operating mechanism.

Reference is now made to FIGS. 3-4 for a specific description of the operation concerning the alternate action mechanism embodiment illustrated in FIGS. 1-4. When the plunger or push button 50 is moved downwardly relative to the hollow casing 20, the resiliently urged lever 70 is moved from the position shown in FIG. 1 through the full to the dotted line position shown in FIG. 3 of the drawings. The lower face of pawl member 80 is maintained in a substantially horizontal position by its third inflexible finger portion 86 in order to position the lower face of first inflexible finger portion 82 in direct, full face engagement first with the leading surface 97 of the engaged ratchet gear tooth and then the upper surface thereof in moving the ratchet gear 94 from the full to the dotted line position shown in FIG. 3.

As the ratchet gear 94 and cam member 96 are operatively interconnected to one another, rotation of the ratchet gear through a predetermined arc will also 'cause movement of the cam member 96 through the same arc. The cam member 96 is provided with half as many tee-th as ratchet `gear 94 so that its teeth will be positioned into cooperation with the depressor plate only on every other depression of the plunger or push 'button 50. The depressor plate 110 has the same number of arms as there are switch actuator or depressor buttons 42, and are also positioned in alignment therewith so that upon engagement of teeth 102 of cam member 96 with one of the arms of depressor plate 110, the switoh actuator or depressor buttons 42 will be depressed for controlling the movement of switch contacts mounted within the switches 40.

Upon each release of the plunger or push button 50, the pawl member 80 must be incapacitated or disabled in a fast and trouble-free manner to permit the lever 70 to be returned to its initial position in FIG. 1 for subsequent actuation or depression thereof. As best seen in FIG. 4, the pawl member 80 is capable of being quickly and effectively disengaged from the ratchet gear by the arrangement of the coil spring 78, the pivot shaft 79, the pawl member 80 and the lever 70 with each other as above described. The pawl member 80 as seen in FIG. 4 is moved from its full line lowermost position upon release of the plunger or push button 50 by engagement of its first finger portion 82 first with the lower surface 101, and then with the trailing surface 99 of one tooth 98 to rotatably displace the pawl member in a counterclockwise direction toward the lever 70 as viewed in FIG. 4. The are through which the pawl member 80 is capable of moving is sufficient to permit the first finger portion 82 to slide away and out of engagement with the teeth 98 of Once the pawl member 80 has been distatably displaces it to the position shown in FIG. 1 of the A modified form yof the present invention is shown `in FIG. of the drawings, and is similar to the FIGS. 1-4 embodiment as indicated by the application of identical reference numerals with the suffix a used to designate like parts. In this embodiment, the lever 70a, rather than being attached to the plunger or push button 50a for reciprocatory movement within the hollow casing 20a, is pivotally mounted to the casing by way of shaft 74a which is adapted to extend through the depending legs or arms 22a, 24a of the casing. The hairpin spring 72a has also been slightly modified from the FIGS. 1 4 embodiment so that the wound coils thereof are positioned in surrounding relationship to the shaft 74a with one end attached to a depending leg of the casing and the other end underlying and abutting the lever 70a to resiliently urge it in an upward direction. This pivoting lever type of arrangement is preferably employed where a separate plunger mechanism is contemplated.

Another modified form of ythe present invention is shown in FIG. 6, and is generally similar to the FIGS.

1-4 embodiments as indicated by the application of identical Ireference numerals with the suffix b used to designate like parts, It will be seen that the switch assembly shown in this embodiment is of the lighted push button variety as shown for example in U.S. Patent No. 3,118,038, dated January 15, 1964. The lamp terminals 120, which are fixedly mounted in place ybetween a pair of switches 4Gb, extend upwardly through suitable openings provided in the lever 7Gb and terminate at its uppermost end in a lamp socket 122 positioned within the bore of the stud or tubular element Zb for receivingv the lamp 124. The plunger or push button 50i) is 'hollow in form'and'surrounds the lamp socket 122 in the'bore of the stud or tubular element 28b. The lower end of the hollow plunger or push button 50]; is integrally.' attached to the lever 70b in the same manner as shown in the FIGS. 1-4 embodiment, while the upper end is adapted to'receive'an overcap 128 of an adequate size to cause depression of the hollow plunger or push button 50h yand its associated lever 7Gb when the overcap 128 is depressed. 'It will'thus be apparent that the alternate action mechanism of the present invention can be incorporated within a lighted push button unit of the type described without hindering or interfer-ring with the operation thereof.

The above description has now made it apparent that the alternate action mechanism of the present invention provides a novel and unique device which can be reliably operated in a fast and repetitive manner over a long period, and thus is desirable for many commercial applications. It is to be understood that while the alternate action mechanism of the present invention is preferably employed in connection with switch assemblies of the type described, it may also be incorporated within or used with other switching units as well as control devices requiring alternate action or operation.

While the preferred embodiments of the present invention have `been shown and described herein, it is obvious that many structural details may be changed without departing from the spirit and scope of the appended claims.

I claim:

1. A switch assembly comprising, in combination, a hollow casing having open ends, at least one switch fixedly mounted relative to said hollow casing adjacent one open end thereof, said switch having spring loaded depressor means for controlling the movement of switch contacts mounted within said switch7 the other end of said hollow casing adapted to receive reciprocating plunger means capable of being moved into and out of said hollow casing, and .alternate action means positioned in said hollow cas- `ing including a resiliently urged lever mounted for movement toward said reciprocating plunger means for cooperative engagement therewith when said plunger means is displaced, a pawl member pivotally mounted to said lever adjacent one end thereof and extending away frpm said lever in a direction generally opposite to that in which the lever is resiliently urged, combination cam-ratchet means rotatably mounted to said casing, the ratchet means being positioned for engagement with said pawl member when said lever is displaced for rotating said cam means alternately into and out of operative engagement with said spring loaded depressor means of said switch, means extending from said pawl member and engaging said lever to maintain the lower lface of said pawl member in a predetermined attitude for positive coaction with said ratchet means when moved into engagement, therewith, and means permitting said pawl mem-ber to be rotatably displaced out of engagement with said ratchet means upon the return of said lever to its linitial position.

2. The structure as defined in claim '1 wherein said lever is resiliently urged toward said plunger means by spring means operatively mounted to said casing.

3. The structure as defined in claim 1 wherein said lever is pivotally mounted vto said casing at an end remote from said pawl member.

4. The structure as defined in claim 1 wherein said lever is mounted for reciprocatory movement within said casing.

casing.'

l 7. The structure asdefined in claim 1 including a depressor plate pivotally mounted to said casing and extending between said cam means and said spring loaded depressor means, said depressor plate having means assofciated therewith'to provide a positive drive connection between said cam means and said spring loaded depressor means while also preventing reverse rotation of said cam means.

' 8. The structure as defined inclaim 7 wherein said last mentioned means includes a detent formed at the outer free extremity of said depressor plate for cooperative engagement with said cam means.l

9. The structure as defined in claim 1 wherein the means for maintaining'thepawl member in a predetermined attitude includes a projecting shoulder integrally `associated with said pawl member which abuts against said lever when said pawl member is attempted to be 'rotated in a given direction.

10. The structure as defined in claim 1 wherein said means permitting lrotatable displacement of said pawl `'member includes a coil spring means positioned between said lever and pawl member.

11. A switch assembly comprising, in combination, a hollow casing having open ends, at least one switch fixedly mounted to said hollow casing adjacent one open end thereof" and having spring loaded depressor means for controlling the Imovement of switch contacts mounted within said switch, the other end of said hollow casing adapted to receive reciprocating plunger means capable of being moved into and out of said hollow casing, and alternate action means positioned in said hollow casing including a lever mounted interiorly of said casing and having spring means associated therewith for resiliently urging the same toward said plunger means for cooperative engagement therewith when said plunger means is displaced, a pawl member pivotally mounted to said lever adjacent one end thereof and having first and second portions extending on opposite sides of the vpivot axis below the lower face of said lever, said first portion being positioned in close proximity to said one end and being restrained from movement toward said leveren one side of its pivot axis, said second portionbeingresiliently urged away from said lever on the other side of said pivot axis, cooperative cam-ratchet means rotatably mounted to said hollow casing, the ratchet means being positioned for engagement with the first portion of said pawl member when said lever is moved by said reciprocating plunger means from a position of rest to a second position for rotating said cam means into and out of operative engagement with the spring loaded depressor means of said switch, the return of said 4lever from the second to its rest position causing movement of the second portion of said pawl member toward the lever to permit the first portion of said pawl member to be disengaged from said ratchet means.

12. An alternate action mechanism positioned between a reciprocable plunger means and a spring loaded actuator button which controls the movement of contact members associated therewith comprising,

(a) lever means yieldably urged toward said plunger means for cooperative engagement therewith when said plunger means is displaced in a first direction,

(b) a pawl member pivotally mounted to said lever adjacent one end thereof and extending away from said lever in a direction generally opposite to that in which the lever is yieldably urged, said pawl member having portions thereof extending on `opposite sides of its pivot axis and being restrained from movement toward said lever on one side of said pivot axis while being resiliently urged away from said lever on lthe other side of said pivot axis, and

(c) unitary cam-ratchet means rotatably mounted for simultaneous operative engagement with said pawl member and said spring with said pawl member on the side thereof restrained from movement when said lever is moved by said reciprocating plunger means for rotating said cam means alternately into and out of operative engagement with said spring loaded actua-tor button, the return of said lever to its initial position upon movement of said reciprocating plunger means in a second direction causing said pawl member to be moved toward said lever on the other side of its pivot axis to permit disengagement from said ratchet means.

13. In a switch assembly of the type having a hollow casing, at least one switch mounted to the casing adjacent one end thereof, and a reciprocating plunger adapted to be received by another portion of said hollow casing, the improvement comprising an alternate action mechanism positioned between said switch and plunger including a lever mounted interiorly of said hollow casing and being resiliently urged toward said plunger for cooperative engagement therewith when said plunger is displaced, a pawl member pivotally mounted to said lever and extending beyond one face thereof in a direction generally opposite to that in which the lever is `resiliently urged, said pawl member having first and second portions extending on opposite sides of its pivot axis, the first portion of said pawl member being restrained from movement toward the lever on one side of its pivot axis, the second portion of said pawl member being resiliently urged away from said lever on the other side of its pivot axis, unitary cam-ratchet means rotatably mounted to said hollow casing for simultaneous operative engagement with said pawl member and a spring loaded actuator button of said switch, the ratchet means being positioned for engagement with the first portion of said pawl member when said lever is moved by said reciprocating plunger for ro-tating said cam means alternately into and out of operative engagement with said spring loaded actuator button, the return of said lever to its initial position causing movement of the second portion of said pawl 5 member toward the lever to permit the first portion of said pawl member to be disengaged from said ratchet means.

14. A switch assembly comprising, in combination,

a hollow casing having open ends,

at least one switch fixedly mounted to said hollow casing adjacent one open end thereof and having rterminals projecting beyond said open end, said switch also having spring loaded depressor means for controlling `the movement of switch contacts mounted within said switch,

reciprocable plunger means capable of being received by the other end of said hollow casing for movement into and out -of the same,

and alternate action means positioned in said hollow casing including:

a lever mounted interiorly of said casing and having spring means associated therewith for resiliently urging said lever toward the plunger means for cooperative engagement therewith when said plunger means is actuated,

a pawl member accepted by a complementary channel formed in said lever adjacent one end thereof and pivotally mounted to said lever therewithin, said pawl member having firs-t and second inflexible finger portions extending on opposite sides of its pivot axis below one face of said lever and a third inflexible finger accepted within the channel and adapted to abut against a marginal portion of said lever surrounding said channel, said first inflexible finger being restrained from movement toward said lever on one side of its pivot .axis by said third inflexible finger, said second inflexible finger being resiliently urged away from said lever on the other side of said pivot axis,

cooperative cam-ratchet means rotatably mounted to said hollow casing, the ratchet means being positioned for engagement with the first inflexible finger of said pawl member when said lever is moved by the reciprocable plunger means from a position of rest to a second position for rot-ating said cam means alternately into and out of operative engagement with the spring loaded depressor means of said switch, said first inflexible finger being maintained in a predetermined attitude by said third inflexible finger as it abuts against said lever to provide posi- 'tive coaction between said 4first inflexible finger and said pawl member, the return of said lever from its second to its rest position upon the withdrawal of said reciprocable plunger means causing movement of the second inflexible finger of said pawl member toward the lever to thereby permit the first inflexible finger of said pawl member to be disengaged from said ratchet means.

References Cited by the Examiner UNITED STATES PATENTS 2,820,113 1/1958 Lewes et al 200-6 3,014,112 12/1961 Millerwise 20G-156 ROBERT K. SCHAEFER, Pfimary Examiner.

H. HOHAUSER. Assistant Examiner. 

12. AN ALTERNATE ACTION MECHANISM POSITIONED BETWEEN A RECIPROCABLE PLUNGER MEANS AND A SPRING LOADED ACTUATOR BUTTON WHICH CONTROLS THE MOVEMENT OF CONTACT MEMBERS ASSOCIATED THEREWITH COMPRISING, (A) LEVER MEANS YIELDABLY URGED TOWARD SAID PLUNGER MEANS FOR COOPERATIVE ENGAGEMENT THEREWITH WHEN SAID PLUNGER MEANS IS DISPLACED IN A FIRST DIRECTION, (B) A PAWL MEMBER PIVOTALLY MOUNTED TO SAID LEVER ADJACENT ONE END THEREOF AND EXTENDING AWAY FROM SAID LEVER IN A DIRECTION GENERALLLY OPPOSITE TO THAT IN WHICH THE LEVER IS YIELDABLY URGED, SAID PAWL MEMBER HAVING PORTIONS THEREOF EXTENDING ON OPPOSITE SIDES OF ITS PIVOT AXIS AND BEING RESTRAINED FROM MOVEMENT TOWARD SAID LEVER ON ONE SIDE OF SAID PIVOT AXIS WHILE BEING RESILIENTLY URGED AWAY FROM SAID LEVER ON THE OTHER SIDE OF SAID PIVOT AXIS, AND (C) UNITARY CAM-RATCHET MEANS ROTATABLY MOUNTED FOR SIMULTANEOUS OPERATIVE ENGAGEMENT WITH SAID PAWL MEMBER AND SAID SPRING WITH SAID PAWL MEMBER ON THE SIDE THEREOF RESTRAINED FROM MOVEMENT WHEN SAID LEVER IS MOVED BY SAID RECIPROCATING PLUNGER MEANS FOR ROTATING SAID CAM MEANS ALTERNATELY INTO AND OUT 